net: hns3: remove redundant memset when alloc buffer

HW will use packet length to write packets to buffer or read
packets from buffer. There is a redundant memset when alloc buffer,
the memset have no sense and will increase time-consuming.
This patch removes it.

Fixes: 76ad4f0e (net: hns3: Add support of HNS3 Ethernet Driver for hip08 SoC)
Signed-off-by: NLipeng <lipeng321@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/hisilicon/hns3/hns3pf/hns3_enet.c

@@ -1444,8 +1444,6 @@ static int hns3_alloc_buffer(struct hns3_enet_ring *ring,
 	cb->length = hnae_page_size(ring);
 	cb->type = DESC_TYPE_PAGE;
 
-	memset(cb->buf, 0, cb->length);
-
 	return 0;
 }